Dell Precision T5500 (Early 2009) - Manual (Page 8)

Exit BIOS <Esc>—Remain in Setup, Save/Exit, Discard/Exit
Change a setting Left- and right-arrow keys
Select field to change <Enter>
Cancel a modification <Esc>
Reset defaults <Alt><F> or Load Defaults menu option
NOTE: Depending on your computer and any installed devices, the items listed in this section may or may not appear.